1. Field of the Invention
The present invention relates to techniques enabling a display of zoom information during zoom operation.
2. Related Art
There are imaging devices such as digital cameras having optical and digital zooming. Optical zooming is what lenses of a digital camera can perform for changing a focal length and a picture angle by changing the positions of some of the lenses. On the other hand, in digital zooming, the digital camera clips some portion of pixel areas captured by an image sensor and electronically enlarges the portion for zoom effect.
Optical zooming controls positions of predetermined lenses so as to change a focal length, allowing the control of a zoom magnification. Digital zooming, on the other hand, clips a captured image data in a predetermined size so as to adjust a picture angle. In addition, digital zooming performs an interpolation for insufficient pixels based on brightness data and the like of adjacent pixels, for example, such that the insufficient pixels are supplemented with to obtain a number of pixels, which is substantially equivalent with that originally acquired. In this way, digital zooming controls the zoom magnification.
In such imaging devices, a current zoom magnification is indicated by a numerical value. Alternatively, as shown in FIGS. 15A and 15B, the current zoom magnification is intuitively displayed in a visual manner with a moving block 172 in a bar graph 170 defined by an optical zoom area 171 and a digital zoom (electronic zoom) area 173.
Japanese Unexamined Patent Application Publication No. 2002-51253 discloses a technique for switching with a common zooming member between optical and digital zooming in electronic imaging devices.
As described above, the zoom information has been conventionally controlled to be displayed in the form of a numerical value or bar. However, general imaging devices, which are widely used mainly for mobile applications, have a display resolution which is lower than that of an image sensor. Accordingly, a user may have been unaware of the degradation of an image when taking a picture while looking at a display of an imaging device.
In addition, a boundary 174 between the optical zoom area 171 and digital zoom area 173, as shown in FIGS. 15A and 15B, does not necessarily indicate a position at which the degradation of an image starts. Furthermore, since the boundary 174 has been conventionally fixed, it has not succeeded in helping the user to capture a desirable image.